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1/*
2 * cn_proc.c - process events connector
3 *
4 * Copyright (C) Matt Helsley, IBM Corp. 2005
5 * Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
6 * Original copyright notice follows:
7 * Copyright (C) 2005 BULL SA.
8 *
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25#include <linux/module.h>
26#include <linux/kernel.h>
27#include <linux/ktime.h>
28#include <linux/init.h>
29#include <linux/connector.h>
30#include <linux/gfp.h>
31#include <linux/ptrace.h>
32#include <linux/atomic.h>
33#include <linux/pid_namespace.h>
34
35#include <linux/cn_proc.h>
36
37/*
38 * Size of a cn_msg followed by a proc_event structure. Since the
39 * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
40 * add one 4-byte word to the size here, and then start the actual
41 * cn_msg structure 4 bytes into the stack buffer. The result is that
42 * the immediately following proc_event structure is aligned to 8 bytes.
43 */
44#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)
45
46/* See comment above; we test our assumption about sizeof struct cn_msg here. */
47static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer)
48{
49 BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
50 return (struct cn_msg *)(buffer + 4);
51}
52
53static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
54static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
55
56/* proc_event_counts is used as the sequence number of the netlink message */
57static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
58
59static inline void get_seq(__u32 *ts, int *cpu)
60{
61 preempt_disable();
62 *ts = __this_cpu_inc_return(proc_event_counts) - 1;
63 *cpu = smp_processor_id();
64 preempt_enable();
65}
66
67void proc_fork_connector(struct task_struct *task)
68{
69 struct cn_msg *msg;
70 struct proc_event *ev;
71 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
72 struct task_struct *parent;
73
74 if (atomic_read(&proc_event_num_listeners) < 1)
75 return;
76
77 msg = buffer_to_cn_msg(buffer);
78 ev = (struct proc_event *)msg->data;
79 memset(&ev->event_data, 0, sizeof(ev->event_data));
80 get_seq(&msg->seq, &ev->cpu);
81 ev->timestamp_ns = ktime_get_ns();
82 ev->what = PROC_EVENT_FORK;
83 rcu_read_lock();
84 parent = rcu_dereference(task->real_parent);
85 ev->event_data.fork.parent_pid = parent->pid;
86 ev->event_data.fork.parent_tgid = parent->tgid;
87 rcu_read_unlock();
88 ev->event_data.fork.child_pid = task->pid;
89 ev->event_data.fork.child_tgid = task->tgid;
90
91 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
92 msg->ack = 0; /* not used */
93 msg->len = sizeof(*ev);
94 msg->flags = 0; /* not used */
95 /* If cn_netlink_send() failed, the data is not sent */
96 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
97}
98
99void proc_exec_connector(struct task_struct *task)
100{
101 struct cn_msg *msg;
102 struct proc_event *ev;
103 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
104
105 if (atomic_read(&proc_event_num_listeners) < 1)
106 return;
107
108 msg = buffer_to_cn_msg(buffer);
109 ev = (struct proc_event *)msg->data;
110 memset(&ev->event_data, 0, sizeof(ev->event_data));
111 get_seq(&msg->seq, &ev->cpu);
112 ev->timestamp_ns = ktime_get_ns();
113 ev->what = PROC_EVENT_EXEC;
114 ev->event_data.exec.process_pid = task->pid;
115 ev->event_data.exec.process_tgid = task->tgid;
116
117 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
118 msg->ack = 0; /* not used */
119 msg->len = sizeof(*ev);
120 msg->flags = 0; /* not used */
121 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
122}
123
124void proc_id_connector(struct task_struct *task, int which_id)
125{
126 struct cn_msg *msg;
127 struct proc_event *ev;
128 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
129 const struct cred *cred;
130
131 if (atomic_read(&proc_event_num_listeners) < 1)
132 return;
133
134 msg = buffer_to_cn_msg(buffer);
135 ev = (struct proc_event *)msg->data;
136 memset(&ev->event_data, 0, sizeof(ev->event_data));
137 ev->what = which_id;
138 ev->event_data.id.process_pid = task->pid;
139 ev->event_data.id.process_tgid = task->tgid;
140 rcu_read_lock();
141 cred = __task_cred(task);
142 if (which_id == PROC_EVENT_UID) {
143 ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid);
144 ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
145 } else if (which_id == PROC_EVENT_GID) {
146 ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
147 ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
148 } else {
149 rcu_read_unlock();
150 return;
151 }
152 rcu_read_unlock();
153 get_seq(&msg->seq, &ev->cpu);
154 ev->timestamp_ns = ktime_get_ns();
155
156 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
157 msg->ack = 0; /* not used */
158 msg->len = sizeof(*ev);
159 msg->flags = 0; /* not used */
160 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
161}
162
163void proc_sid_connector(struct task_struct *task)
164{
165 struct cn_msg *msg;
166 struct proc_event *ev;
167 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
168
169 if (atomic_read(&proc_event_num_listeners) < 1)
170 return;
171
172 msg = buffer_to_cn_msg(buffer);
173 ev = (struct proc_event *)msg->data;
174 memset(&ev->event_data, 0, sizeof(ev->event_data));
175 get_seq(&msg->seq, &ev->cpu);
176 ev->timestamp_ns = ktime_get_ns();
177 ev->what = PROC_EVENT_SID;
178 ev->event_data.sid.process_pid = task->pid;
179 ev->event_data.sid.process_tgid = task->tgid;
180
181 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
182 msg->ack = 0; /* not used */
183 msg->len = sizeof(*ev);
184 msg->flags = 0; /* not used */
185 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
186}
187
188void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
189{
190 struct cn_msg *msg;
191 struct proc_event *ev;
192 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
193
194 if (atomic_read(&proc_event_num_listeners) < 1)
195 return;
196
197 msg = buffer_to_cn_msg(buffer);
198 ev = (struct proc_event *)msg->data;
199 memset(&ev->event_data, 0, sizeof(ev->event_data));
200 get_seq(&msg->seq, &ev->cpu);
201 ev->timestamp_ns = ktime_get_ns();
202 ev->what = PROC_EVENT_PTRACE;
203 ev->event_data.ptrace.process_pid = task->pid;
204 ev->event_data.ptrace.process_tgid = task->tgid;
205 if (ptrace_id == PTRACE_ATTACH) {
206 ev->event_data.ptrace.tracer_pid = current->pid;
207 ev->event_data.ptrace.tracer_tgid = current->tgid;
208 } else if (ptrace_id == PTRACE_DETACH) {
209 ev->event_data.ptrace.tracer_pid = 0;
210 ev->event_data.ptrace.tracer_tgid = 0;
211 } else
212 return;
213
214 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
215 msg->ack = 0; /* not used */
216 msg->len = sizeof(*ev);
217 msg->flags = 0; /* not used */
218 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
219}
220
221void proc_comm_connector(struct task_struct *task)
222{
223 struct cn_msg *msg;
224 struct proc_event *ev;
225 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
226
227 if (atomic_read(&proc_event_num_listeners) < 1)
228 return;
229
230 msg = buffer_to_cn_msg(buffer);
231 ev = (struct proc_event *)msg->data;
232 memset(&ev->event_data, 0, sizeof(ev->event_data));
233 get_seq(&msg->seq, &ev->cpu);
234 ev->timestamp_ns = ktime_get_ns();
235 ev->what = PROC_EVENT_COMM;
236 ev->event_data.comm.process_pid = task->pid;
237 ev->event_data.comm.process_tgid = task->tgid;
238 get_task_comm(ev->event_data.comm.comm, task);
239
240 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
241 msg->ack = 0; /* not used */
242 msg->len = sizeof(*ev);
243 msg->flags = 0; /* not used */
244 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
245}
246
247void proc_coredump_connector(struct task_struct *task)
248{
249 struct cn_msg *msg;
250 struct proc_event *ev;
251 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
252
253 if (atomic_read(&proc_event_num_listeners) < 1)
254 return;
255
256 msg = buffer_to_cn_msg(buffer);
257 ev = (struct proc_event *)msg->data;
258 memset(&ev->event_data, 0, sizeof(ev->event_data));
259 get_seq(&msg->seq, &ev->cpu);
260 ev->timestamp_ns = ktime_get_ns();
261 ev->what = PROC_EVENT_COREDUMP;
262 ev->event_data.coredump.process_pid = task->pid;
263 ev->event_data.coredump.process_tgid = task->tgid;
264
265 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
266 msg->ack = 0; /* not used */
267 msg->len = sizeof(*ev);
268 msg->flags = 0; /* not used */
269 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
270}
271
272void proc_exit_connector(struct task_struct *task)
273{
274 struct cn_msg *msg;
275 struct proc_event *ev;
276 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
277
278 if (atomic_read(&proc_event_num_listeners) < 1)
279 return;
280
281 msg = buffer_to_cn_msg(buffer);
282 ev = (struct proc_event *)msg->data;
283 memset(&ev->event_data, 0, sizeof(ev->event_data));
284 get_seq(&msg->seq, &ev->cpu);
285 ev->timestamp_ns = ktime_get_ns();
286 ev->what = PROC_EVENT_EXIT;
287 ev->event_data.exit.process_pid = task->pid;
288 ev->event_data.exit.process_tgid = task->tgid;
289 ev->event_data.exit.exit_code = task->exit_code;
290 ev->event_data.exit.exit_signal = task->exit_signal;
291
292 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
293 msg->ack = 0; /* not used */
294 msg->len = sizeof(*ev);
295 msg->flags = 0; /* not used */
296 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
297}
298
299/*
300 * Send an acknowledgement message to userspace
301 *
302 * Use 0 for success, EFOO otherwise.
303 * Note: this is the negative of conventional kernel error
304 * values because it's not being returned via syscall return
305 * mechanisms.
306 */
307static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
308{
309 struct cn_msg *msg;
310 struct proc_event *ev;
311 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
312
313 if (atomic_read(&proc_event_num_listeners) < 1)
314 return;
315
316 msg = buffer_to_cn_msg(buffer);
317 ev = (struct proc_event *)msg->data;
318 memset(&ev->event_data, 0, sizeof(ev->event_data));
319 msg->seq = rcvd_seq;
320 ev->timestamp_ns = ktime_get_ns();
321 ev->cpu = -1;
322 ev->what = PROC_EVENT_NONE;
323 ev->event_data.ack.err = err;
324 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
325 msg->ack = rcvd_ack + 1;
326 msg->len = sizeof(*ev);
327 msg->flags = 0; /* not used */
328 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
329}
330
331/**
332 * cn_proc_mcast_ctl
333 * @data: message sent from userspace via the connector
334 */
335static void cn_proc_mcast_ctl(struct cn_msg *msg,
336 struct netlink_skb_parms *nsp)
337{
338 enum proc_cn_mcast_op *mc_op = NULL;
339 int err = 0;
340
341 if (msg->len != sizeof(*mc_op))
342 return;
343
344 /*
345 * Events are reported with respect to the initial pid
346 * and user namespaces so ignore requestors from
347 * other namespaces.
348 */
349 if ((current_user_ns() != &init_user_ns) ||
350 (task_active_pid_ns(current) != &init_pid_ns))
351 return;
352
353 /* Can only change if privileged. */
354 if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
355 err = EPERM;
356 goto out;
357 }
358
359 mc_op = (enum proc_cn_mcast_op *)msg->data;
360 switch (*mc_op) {
361 case PROC_CN_MCAST_LISTEN:
362 atomic_inc(&proc_event_num_listeners);
363 break;
364 case PROC_CN_MCAST_IGNORE:
365 atomic_dec(&proc_event_num_listeners);
366 break;
367 default:
368 err = EINVAL;
369 break;
370 }
371
372out:
373 cn_proc_ack(err, msg->seq, msg->ack);
374}
375
376/*
377 * cn_proc_init - initialization entry point
378 *
379 * Adds the connector callback to the connector driver.
380 */
381static int __init cn_proc_init(void)
382{
383 int err = cn_add_callback(&cn_proc_event_id,
384 "cn_proc",
385 &cn_proc_mcast_ctl);
386 if (err) {
387 pr_warn("cn_proc failed to register\n");
388 return err;
389 }
390 return 0;
391}
392
393module_init(cn_proc_init);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * cn_proc.c - process events connector
4 *
5 * Copyright (C) Matt Helsley, IBM Corp. 2005
6 * Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
7 * Original copyright notice follows:
8 * Copyright (C) 2005 BULL SA.
9 */
10
11#include <linux/kernel.h>
12#include <linux/ktime.h>
13#include <linux/init.h>
14#include <linux/connector.h>
15#include <linux/gfp.h>
16#include <linux/ptrace.h>
17#include <linux/atomic.h>
18#include <linux/pid_namespace.h>
19
20#include <linux/cn_proc.h>
21
22/*
23 * Size of a cn_msg followed by a proc_event structure. Since the
24 * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
25 * add one 4-byte word to the size here, and then start the actual
26 * cn_msg structure 4 bytes into the stack buffer. The result is that
27 * the immediately following proc_event structure is aligned to 8 bytes.
28 */
29#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)
30
31/* See comment above; we test our assumption about sizeof struct cn_msg here. */
32static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer)
33{
34 BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
35 return (struct cn_msg *)(buffer + 4);
36}
37
38static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
39static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
40
41/* proc_event_counts is used as the sequence number of the netlink message */
42static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
43
44static inline void send_msg(struct cn_msg *msg)
45{
46 preempt_disable();
47
48 msg->seq = __this_cpu_inc_return(proc_event_counts) - 1;
49 ((struct proc_event *)msg->data)->cpu = smp_processor_id();
50
51 /*
52 * Preemption remains disabled during send to ensure the messages are
53 * ordered according to their sequence numbers.
54 *
55 * If cn_netlink_send() fails, the data is not sent.
56 */
57 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
58
59 preempt_enable();
60}
61
62void proc_fork_connector(struct task_struct *task)
63{
64 struct cn_msg *msg;
65 struct proc_event *ev;
66 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
67 struct task_struct *parent;
68
69 if (atomic_read(&proc_event_num_listeners) < 1)
70 return;
71
72 msg = buffer_to_cn_msg(buffer);
73 ev = (struct proc_event *)msg->data;
74 memset(&ev->event_data, 0, sizeof(ev->event_data));
75 ev->timestamp_ns = ktime_get_ns();
76 ev->what = PROC_EVENT_FORK;
77 rcu_read_lock();
78 parent = rcu_dereference(task->real_parent);
79 ev->event_data.fork.parent_pid = parent->pid;
80 ev->event_data.fork.parent_tgid = parent->tgid;
81 rcu_read_unlock();
82 ev->event_data.fork.child_pid = task->pid;
83 ev->event_data.fork.child_tgid = task->tgid;
84
85 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
86 msg->ack = 0; /* not used */
87 msg->len = sizeof(*ev);
88 msg->flags = 0; /* not used */
89 send_msg(msg);
90}
91
92void proc_exec_connector(struct task_struct *task)
93{
94 struct cn_msg *msg;
95 struct proc_event *ev;
96 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
97
98 if (atomic_read(&proc_event_num_listeners) < 1)
99 return;
100
101 msg = buffer_to_cn_msg(buffer);
102 ev = (struct proc_event *)msg->data;
103 memset(&ev->event_data, 0, sizeof(ev->event_data));
104 ev->timestamp_ns = ktime_get_ns();
105 ev->what = PROC_EVENT_EXEC;
106 ev->event_data.exec.process_pid = task->pid;
107 ev->event_data.exec.process_tgid = task->tgid;
108
109 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
110 msg->ack = 0; /* not used */
111 msg->len = sizeof(*ev);
112 msg->flags = 0; /* not used */
113 send_msg(msg);
114}
115
116void proc_id_connector(struct task_struct *task, int which_id)
117{
118 struct cn_msg *msg;
119 struct proc_event *ev;
120 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
121 const struct cred *cred;
122
123 if (atomic_read(&proc_event_num_listeners) < 1)
124 return;
125
126 msg = buffer_to_cn_msg(buffer);
127 ev = (struct proc_event *)msg->data;
128 memset(&ev->event_data, 0, sizeof(ev->event_data));
129 ev->what = which_id;
130 ev->event_data.id.process_pid = task->pid;
131 ev->event_data.id.process_tgid = task->tgid;
132 rcu_read_lock();
133 cred = __task_cred(task);
134 if (which_id == PROC_EVENT_UID) {
135 ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid);
136 ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
137 } else if (which_id == PROC_EVENT_GID) {
138 ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
139 ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
140 } else {
141 rcu_read_unlock();
142 return;
143 }
144 rcu_read_unlock();
145 ev->timestamp_ns = ktime_get_ns();
146
147 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
148 msg->ack = 0; /* not used */
149 msg->len = sizeof(*ev);
150 msg->flags = 0; /* not used */
151 send_msg(msg);
152}
153
154void proc_sid_connector(struct task_struct *task)
155{
156 struct cn_msg *msg;
157 struct proc_event *ev;
158 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
159
160 if (atomic_read(&proc_event_num_listeners) < 1)
161 return;
162
163 msg = buffer_to_cn_msg(buffer);
164 ev = (struct proc_event *)msg->data;
165 memset(&ev->event_data, 0, sizeof(ev->event_data));
166 ev->timestamp_ns = ktime_get_ns();
167 ev->what = PROC_EVENT_SID;
168 ev->event_data.sid.process_pid = task->pid;
169 ev->event_data.sid.process_tgid = task->tgid;
170
171 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
172 msg->ack = 0; /* not used */
173 msg->len = sizeof(*ev);
174 msg->flags = 0; /* not used */
175 send_msg(msg);
176}
177
178void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
179{
180 struct cn_msg *msg;
181 struct proc_event *ev;
182 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
183
184 if (atomic_read(&proc_event_num_listeners) < 1)
185 return;
186
187 msg = buffer_to_cn_msg(buffer);
188 ev = (struct proc_event *)msg->data;
189 memset(&ev->event_data, 0, sizeof(ev->event_data));
190 ev->timestamp_ns = ktime_get_ns();
191 ev->what = PROC_EVENT_PTRACE;
192 ev->event_data.ptrace.process_pid = task->pid;
193 ev->event_data.ptrace.process_tgid = task->tgid;
194 if (ptrace_id == PTRACE_ATTACH) {
195 ev->event_data.ptrace.tracer_pid = current->pid;
196 ev->event_data.ptrace.tracer_tgid = current->tgid;
197 } else if (ptrace_id == PTRACE_DETACH) {
198 ev->event_data.ptrace.tracer_pid = 0;
199 ev->event_data.ptrace.tracer_tgid = 0;
200 } else
201 return;
202
203 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
204 msg->ack = 0; /* not used */
205 msg->len = sizeof(*ev);
206 msg->flags = 0; /* not used */
207 send_msg(msg);
208}
209
210void proc_comm_connector(struct task_struct *task)
211{
212 struct cn_msg *msg;
213 struct proc_event *ev;
214 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
215
216 if (atomic_read(&proc_event_num_listeners) < 1)
217 return;
218
219 msg = buffer_to_cn_msg(buffer);
220 ev = (struct proc_event *)msg->data;
221 memset(&ev->event_data, 0, sizeof(ev->event_data));
222 ev->timestamp_ns = ktime_get_ns();
223 ev->what = PROC_EVENT_COMM;
224 ev->event_data.comm.process_pid = task->pid;
225 ev->event_data.comm.process_tgid = task->tgid;
226 get_task_comm(ev->event_data.comm.comm, task);
227
228 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
229 msg->ack = 0; /* not used */
230 msg->len = sizeof(*ev);
231 msg->flags = 0; /* not used */
232 send_msg(msg);
233}
234
235void proc_coredump_connector(struct task_struct *task)
236{
237 struct cn_msg *msg;
238 struct proc_event *ev;
239 struct task_struct *parent;
240 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
241
242 if (atomic_read(&proc_event_num_listeners) < 1)
243 return;
244
245 msg = buffer_to_cn_msg(buffer);
246 ev = (struct proc_event *)msg->data;
247 memset(&ev->event_data, 0, sizeof(ev->event_data));
248 ev->timestamp_ns = ktime_get_ns();
249 ev->what = PROC_EVENT_COREDUMP;
250 ev->event_data.coredump.process_pid = task->pid;
251 ev->event_data.coredump.process_tgid = task->tgid;
252
253 rcu_read_lock();
254 if (pid_alive(task)) {
255 parent = rcu_dereference(task->real_parent);
256 ev->event_data.coredump.parent_pid = parent->pid;
257 ev->event_data.coredump.parent_tgid = parent->tgid;
258 }
259 rcu_read_unlock();
260
261 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
262 msg->ack = 0; /* not used */
263 msg->len = sizeof(*ev);
264 msg->flags = 0; /* not used */
265 send_msg(msg);
266}
267
268void proc_exit_connector(struct task_struct *task)
269{
270 struct cn_msg *msg;
271 struct proc_event *ev;
272 struct task_struct *parent;
273 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
274
275 if (atomic_read(&proc_event_num_listeners) < 1)
276 return;
277
278 msg = buffer_to_cn_msg(buffer);
279 ev = (struct proc_event *)msg->data;
280 memset(&ev->event_data, 0, sizeof(ev->event_data));
281 ev->timestamp_ns = ktime_get_ns();
282 ev->what = PROC_EVENT_EXIT;
283 ev->event_data.exit.process_pid = task->pid;
284 ev->event_data.exit.process_tgid = task->tgid;
285 ev->event_data.exit.exit_code = task->exit_code;
286 ev->event_data.exit.exit_signal = task->exit_signal;
287
288 rcu_read_lock();
289 if (pid_alive(task)) {
290 parent = rcu_dereference(task->real_parent);
291 ev->event_data.exit.parent_pid = parent->pid;
292 ev->event_data.exit.parent_tgid = parent->tgid;
293 }
294 rcu_read_unlock();
295
296 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
297 msg->ack = 0; /* not used */
298 msg->len = sizeof(*ev);
299 msg->flags = 0; /* not used */
300 send_msg(msg);
301}
302
303/*
304 * Send an acknowledgement message to userspace
305 *
306 * Use 0 for success, EFOO otherwise.
307 * Note: this is the negative of conventional kernel error
308 * values because it's not being returned via syscall return
309 * mechanisms.
310 */
311static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
312{
313 struct cn_msg *msg;
314 struct proc_event *ev;
315 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
316
317 if (atomic_read(&proc_event_num_listeners) < 1)
318 return;
319
320 msg = buffer_to_cn_msg(buffer);
321 ev = (struct proc_event *)msg->data;
322 memset(&ev->event_data, 0, sizeof(ev->event_data));
323 msg->seq = rcvd_seq;
324 ev->timestamp_ns = ktime_get_ns();
325 ev->cpu = -1;
326 ev->what = PROC_EVENT_NONE;
327 ev->event_data.ack.err = err;
328 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
329 msg->ack = rcvd_ack + 1;
330 msg->len = sizeof(*ev);
331 msg->flags = 0; /* not used */
332 send_msg(msg);
333}
334
335/**
336 * cn_proc_mcast_ctl
337 * @data: message sent from userspace via the connector
338 */
339static void cn_proc_mcast_ctl(struct cn_msg *msg,
340 struct netlink_skb_parms *nsp)
341{
342 enum proc_cn_mcast_op *mc_op = NULL;
343 int err = 0;
344
345 if (msg->len != sizeof(*mc_op))
346 return;
347
348 /*
349 * Events are reported with respect to the initial pid
350 * and user namespaces so ignore requestors from
351 * other namespaces.
352 */
353 if ((current_user_ns() != &init_user_ns) ||
354 (task_active_pid_ns(current) != &init_pid_ns))
355 return;
356
357 /* Can only change if privileged. */
358 if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
359 err = EPERM;
360 goto out;
361 }
362
363 mc_op = (enum proc_cn_mcast_op *)msg->data;
364 switch (*mc_op) {
365 case PROC_CN_MCAST_LISTEN:
366 atomic_inc(&proc_event_num_listeners);
367 break;
368 case PROC_CN_MCAST_IGNORE:
369 atomic_dec(&proc_event_num_listeners);
370 break;
371 default:
372 err = EINVAL;
373 break;
374 }
375
376out:
377 cn_proc_ack(err, msg->seq, msg->ack);
378}
379
380/*
381 * cn_proc_init - initialization entry point
382 *
383 * Adds the connector callback to the connector driver.
384 */
385static int __init cn_proc_init(void)
386{
387 int err = cn_add_callback(&cn_proc_event_id,
388 "cn_proc",
389 &cn_proc_mcast_ctl);
390 if (err) {
391 pr_warn("cn_proc failed to register\n");
392 return err;
393 }
394 return 0;
395}
396device_initcall(cn_proc_init);